The loggerhead sea turtles are reptiles that grow to almost one metre in length. Although they breathe air using their lungs, they spend almost all of their life underwater, feeding on jellyfish, molluscs and other invertebrates.
In earlyspring, the turtles migrate from the C. Mediterranean foraging areas to Laganas Bay to mate, and nest on the beaches from mid-May to late-August. At night, females come ashore, choose a suitable spot, and use their flippers to dig an egg chamber, which is 40-50 cm deep. Here, they lay a clutch of 120 eggs on average. This process is repeated 3-4 times throughout the summer. The eggs resemble a «ping-pong ball» in size and shape, but have a soft shell so as not to break when they drop into the nest. The eggs incubate in the nest for 42-70 days, of which 60-70% hatch. Sand temperature determines the sex of the offspring (hatchlings); above 29οC, the hatchlings are primarily female, while below this temperature they are primarily male.
Hatchlings are approximately 5 cm long and usually emerge from the nest at night. They find their way to the sea assisted by the stars and by moonlight eflected off the water. As they leave the nest and crawl to the sea, hatchlings are thought to imprint the location by a ‘magnetic compass’. This is a natural process, so, years later, they may return to the same area to breed (termed ‘homing’ behaviour).
The N.M.P.Z. Research Programme ‘Caretta Odyssey’ revealed that turtles breeding on Zakynthos disperse to foraging areas throughout the entire Mediterranean region.